/*
 *
 * Copyright 2016 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
#include <grpc/support/port_platform.h>

#include "src/core/lib/iomgr/port.h"

#ifdef GRPC_HAVE_LINUX_VSOCK

#include <sys/socket.h>
#include <linux/vm_sockets.h>

#endif /* GRPC_HAVE_LINUX_VSOCK */

#ifdef GRPC_HAVE_UNIX_SOCKET

#include "src/core/lib/iomgr/sockaddr.h"

#include <cstdio>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/un.h>

#include "src/core/lib/iomgr/unix_sockets_posix.h"

#include <grpc/support/alloc.h>
#include <grpc/support/log.h>

#include "src/core/lib/gpr/useful.h"

void grpc_create_socketpair_if_unix(int sv[2]) {
  GPR_ASSERT(socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == 0);
}

grpc_error* grpc_resolve_unix_domain_address(const char* name,
                                             grpc_resolved_addresses** addrs) {
  struct sockaddr_un* un;
  if (strlen(name) >
      GPR_ARRAY_SIZE(((struct sockaddr_un*)nullptr)->sun_path) - 1) {
    char* err_msg;
    grpc_error* err;
    gpr_asprintf(&err_msg,
                 "Path name should not have more than %" PRIuPTR " characters.",
                 GPR_ARRAY_SIZE(un->sun_path) - 1);
    err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(err_msg);
    gpr_free(err_msg);
    return err;
  }
  *addrs = static_cast<grpc_resolved_addresses*>(
      gpr_malloc(sizeof(grpc_resolved_addresses)));
  (*addrs)->naddrs = 1;
  (*addrs)->addrs = static_cast<grpc_resolved_address*>(
      gpr_malloc(sizeof(grpc_resolved_address)));
  un = reinterpret_cast<struct sockaddr_un*>((*addrs)->addrs->addr);
  un->sun_family = AF_UNIX;
  strncpy(un->sun_path, name, sizeof(un->sun_path));
  (*addrs)->addrs->len =
      static_cast<socklen_t>(strlen(un->sun_path) + sizeof(un->sun_family) + 1);
  return GRPC_ERROR_NONE;
}

grpc_error* grpc_resolve_vsock_address(const char* name,
                                       grpc_resolved_addresses** addrs) {
#ifdef GRPC_HAVE_LINUX_VSOCK
  struct sockaddr_vm *vm;
  unsigned int cid;
  unsigned int port;

  if (sscanf(name, "%u:%u", &cid, &port) != 2) {
    return GRPC_ERROR_CREATE_FROM_STATIC_STRING("Failed to parse cid:port pair");
  }

  *addrs = static_cast<grpc_resolved_addresses*>(
      gpr_malloc(sizeof(grpc_resolved_addresses)));
  (*addrs)->naddrs = 1;
  (*addrs)->addrs = static_cast<grpc_resolved_address*>(
      gpr_zalloc(sizeof(grpc_resolved_address)));
  vm = (struct sockaddr_vm *)(*addrs)->addrs->addr;
  vm->svm_family = AF_VSOCK;
  vm->svm_cid = cid;
  vm->svm_port = port;
  (*addrs)->addrs->len = sizeof(struct sockaddr_vm);
  return GRPC_ERROR_NONE;
#else /* GRPC_HAVE_LINUX_VSOCK */
  return GRPC_ERROR_CREATE_FROM_STATIC_STRING("vsock not supported");
#endif /* GRPC_HAVE_LINUX_VSOCK */
}

int grpc_is_unix_socket(const grpc_resolved_address* resolved_addr) {
  const grpc_sockaddr* addr =
      reinterpret_cast<const grpc_sockaddr*>(resolved_addr->addr);
  return addr->sa_family == AF_UNIX;
}

int grpc_is_vsock(const grpc_resolved_address* resolved_addr) {
#ifdef GRPC_HAVE_LINUX_VSOCK
  const grpc_sockaddr* addr =
      reinterpret_cast<const grpc_sockaddr*>(resolved_addr->addr);
  return addr->sa_family == AF_VSOCK;
#else /* GRPC_HAVE_LINUX_VSOCK */
  return 0;
#endif /* GRPC_HAVE_LINUX_VSOCK */
}

void grpc_unlink_if_unix_domain_socket(
    const grpc_resolved_address* resolved_addr) {
  const grpc_sockaddr* addr =
      reinterpret_cast<const grpc_sockaddr*>(resolved_addr->addr);
  if (addr->sa_family != AF_UNIX) {
    return;
  }
  struct sockaddr_un* un = reinterpret_cast<struct sockaddr_un*>(
      const_cast<char*>(resolved_addr->addr));
  struct stat st;

  if (stat(un->sun_path, &st) == 0 && (st.st_mode & S_IFMT) == S_IFSOCK) {
    unlink(un->sun_path);
  }
}

char* grpc_sockaddr_to_uri_unix_if_possible(
    const grpc_resolved_address* resolved_addr) {
  const grpc_sockaddr* addr =
      reinterpret_cast<const grpc_sockaddr*>(resolved_addr->addr);
  if (addr->sa_family != AF_UNIX) {
    return nullptr;
  }

  char* result;
  gpr_asprintf(&result, "unix:%s", ((struct sockaddr_un*)addr)->sun_path);
  return result;
}

char* grpc_sockaddr_to_uri_vsock_if_possible(
    const grpc_resolved_address* resolved_addr) {
#ifdef GRPC_HAVE_LINUX_VSOCK
  const grpc_sockaddr* addr =
      reinterpret_cast<const grpc_sockaddr*>(resolved_addr->addr);

  if (addr->sa_family != AF_VSOCK) {
      return nullptr;
  }

  char *result;
  struct sockaddr_vm *vm = (struct sockaddr_vm*)addr;
  gpr_asprintf(&result, "vsock:%u:%u", vm->svm_cid, vm->svm_port);
  return result;
#else /* GRPC_HAVE_LINUX_VSOCK */
  return nullptr;
#endif /* GRPC_HAVE_LINUX_VSOCK */
}

#endif